Special-Purpose Diodes

MCQsQuestion.com has 21 Question/Answers about Topic Special-Purpose Diodes

Back-to-back varactor diodes are used for what reason?

Back-to-back varactor diodes are used for what reason?
  • A. over-voltage protection
  • B. a wider tuning range
  • C. to eliminate harmonic distortion
  • D. no reason; only zeners are used in a back-to-back configuration
  • Correct Answer: Option C

What diode is used in seven-segment displays?

What diode is used in seven-segment displays?
  • A. zener
  • B. LED
  • C. laser
  • D. Schottky
  • Correct Answer: Option B

Which diode employs graded doping?

Which diode employs graded doping?
  • A. zener
  • B. LED
  • C. tunnel
  • D. step-recovery
  • Correct Answer: Option D

What kind of diode is formed by joining a doped semiconductor region with a metal?

What kind of diode is formed by joining a doped semiconductor region with a metal?
  • A. laser
  • B. tunnel
  • C. pin
  • D. Schottky
  • Correct Answer: Option D

What diode operates only with majority carriers?

What diode operates only with majority carriers?
  • A. laser
  • B. tunnel
  • C. Schottky
  • D. step-recovery
  • Correct Answer: Option C

What type of diode maintains a constant current?

What type of diode maintains a constant current?
  • A. LED
  • B. zener
  • C. current regulator
  • D. pin
  • Correct Answer: Option C

LEDs are made out of

LEDs are made out of
  • A. silicon.
  • B. germanium.
  • C. gallium.
  • D. silicon and germanium, but not gallium.
  • Correct Answer: Option C

A varactor is a pn junction diode that always operates in ________-bias and is doped to ________ the inherent capacitance of the depletion region.

A varactor is a pn junction diode that always operates in ________-bias and is doped to ________ the inherent capacitance of the depletion region.
  • A. forward, maximize
  • B. reverse, maximize
  • C. reverse, minimize
  • D. forward, minimize
  • Correct Answer: Option B

What type of diode is commonly used in electronic tuners in TVs?

What type of diode is commonly used in electronic tuners in TVs?
  • A. varactor
  • B. Schottky
  • C. LED
  • D. Gunn
  • Correct Answer: Option A

Zener diodes with breakdown voltages greater than 5 V operate predominantly in what type of breakdown?

Zener diodes with breakdown voltages greater than 5 V operate predominantly in what type of breakdown?
  • A. avalanche
  • B. zener
  • C. varactor
  • D. Schottky
  • Correct Answer: Option A

Zener diodes with breakdown voltages less than 5 V operate predominantly in what type of breakdown?

Zener diodes with breakdown voltages less than 5 V operate predominantly in what type of breakdown?
  • A. avalanche
  • B. zener
  • C. varactor
  • D. Schottky
  • Correct Answer: Option B

You have an application for a diode to be used in a tuning circuit. A type of diode to use might be

You have an application for a diode to be used in a tuning circuit. A type of diode to use might be
  • A. an LED.
  • B. a Schottky diode.
  • C. a Gunn diode.
  • D. a varactor.
  • Correct Answer: Option D

A tunnel diode is used

A tunnel diode is used
  • A. in high-power circuits.
  • B. in circuits requiring negative resistance.
  • C. in very fast-switching circuits.
  • D. in power supply rectifiers.
  • Correct Answer: Option B

The Schottky diode is used

The Schottky diode is used
  • A. in high-power circuits.
  • B. in circuits requiring negative resistance.
  • C. in very fast-switching circuits.
  • D. in power supply rectifiers.
  • Correct Answer: Option C

An LED is forward-biased. The diode should be on, but no light is showing. A possible trouble might be

An LED is forward-biased. The diode should be on, but no light is showing. A possible trouble might be
  • A. the diode is open.
  • B. the series resistor is too small.
  • C. none. The diode should be off if forward-biased.
  • D. the power supply voltage is too high.
  • Correct Answer: Option A
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